IPA: /ˈdʒuː.əl.ər/
KK: /ˈdʒuːələr/
A person who makes, sells, or repairs jewelry.
The jeweller crafted a beautiful ring for the customer.
Jeweller → It is formed from "jewel" (from Old French *juel*, meaning precious stone or ornament) and "-er" (meaning a person who). A jeweller is a person who works with or sells jewels or precious ornaments.
Think of someone who works with 'jewels' — the '-er' just means a person. A jeweller is someone who deals with precious stones.